Unable to start Omnisharp (SonarLint for Rider)

I have SonarLint for Rider 5.2.0.35150, and I get this error in one of my solutions, whenever a C# file gets analyzed. The analysis hangs. Restarting the IDE does not help.

I tried to open another solution and everything works fine.

Error running SonarLint analysis
java.lang.IllegalStateException: Unable to start OmniSharp
	at org.sonarsource.sonarlint.omnisharp.OmnisharpSensor.execute(OmnisharpSensor.java:101)
	at org.sonarsource.sonarlint.core.analyzer.sensor.SensorsExecutor.executeSensor(SensorsExecutor.java:80)
	at org.sonarsource.sonarlint.core.analyzer.sensor.SensorsExecutor.execute(SensorsExecutor.java:71)
	at org.sonarsource.sonarlint.core.container.analysis.AnalysisContainer.doAfterStart(AnalysisContainer.java:133)
	at org.sonarsource.sonarlint.core.container.ComponentContainer.startComponents(ComponentContainer.java:126)
	at org.sonarsource.sonarlint.core.container.ComponentContainer.execute(ComponentContainer.java:111)
	at org.sonarsource.sonarlint.core.container.standalone.StandaloneGlobalContainer.analyze(StandaloneGlobalContainer.java:162)
	at org.sonarsource.sonarlint.core.StandaloneSonarLintEngineImpl.lambda$analyze$0(StandaloneSonarLintEngineImpl.java:95)
	at org.sonarsource.sonarlint.core.AbstractSonarLintEngine.withModule(AbstractSonarLintEngine.java:87)
	at org.sonarsource.sonarlint.core.StandaloneSonarLintEngineImpl.analyze(StandaloneSonarLintEngineImpl.java:93)
	at org.sonarlint.intellij.core.StandaloneSonarLintFacade.analyze(StandaloneSonarLintFacade.java:91)
	at org.sonarlint.intellij.core.SonarLintFacade.startAnalysis(SonarLintFacade.java:64)
	at org.sonarlint.intellij.analysis.SonarLintAnalyzer.analyzeModule(SonarLintAnalyzer.java:93)
	at org.sonarlint.intellij.analysis.AnalysisTask.analyzePerModule(AnalysisTask.java:387)
	at org.sonarlint.intellij.analysis.AnalysisTask.run(AnalysisTask.java:155)
	at com.intellij.openapi.progress.impl.CoreProgressManager$TaskRunnable.run(CoreProgressManager.java:998)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcessWithProgressAsync$5(CoreProgressManager.java:497)
	at com.intellij.openapi.progress.impl.ProgressRunner.lambda$submit$3(ProgressRunner.java:228)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$2(CoreProgressManager.java:178)
	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:688)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:634)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:64)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:165)
	at com.intellij.openapi.progress.impl.ProgressRunner.lambda$submit$4(ProgressRunner.java:228)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1700)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:668)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:665)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1.run(Executors.java:665)
	at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.IllegalStateException: Timeout waiting for solution/project configuration to be loaded
	at org.sonarsource.sonarlint.omnisharp.OmnisharpServer.doStart(OmnisharpServer.java:196)
	at org.sonarsource.sonarlint.omnisharp.OmnisharpServer.lazyStart(OmnisharpServer.java:147)
	at org.sonarsource.sonarlint.omnisharp.OmnisharpSensor.execute(OmnisharpSensor.java:95)
	... 31 more

Hi @Samuel_Langlois

To investigate the issue, could you please enable analysis and verbose logs in the SonarLint Console for this solution, and reopen it. It should display OmniSharp startup logs.
I’m also interested by:

  • your operating system details
  • your mono version
  • your dotnet CLI version
  • anything particular with this solution compared to others that are working (bigger? different project types?)

Thanks,